When sample_hold_time is zero (this is the case when DT is not used or if atmel,adc-sample-hold-time is omitted), then the calculated shtim is large. Make that 0, which is the default for that register and the ADC will then use a sane value of 2/ADCCLK or 1/ADCCLK depending on the version. Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> --- drivers/iio/adc/at91_adc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c index 5b1aa027c034..0b103f905607 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c @@ -1004,8 +1004,11 @@ static int at91_adc_probe(struct platform_device *pdev) * the best converted final value between two channels selection * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock */ - shtim = round_up((st->sample_hold_time * adc_clk_khz / - 1000) - 1, 1); + if (st->sample_hold_time > 0) + shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000) + - 1, 1); + else + shtim = 0; reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask; reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask; -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
